• Hemobilia after the inception of percutaneous transhepatic biliary drainage (PTBD) has been reported as an uncommon, but sometimes fatal, complication. We examined the incidence, pathogenesis, and management of hemobilia in 94 patients who received PTBD. There were seven cases (7.4%) with transient and six (6.4%) with severe hemobilia; one patient (1.1%) of the latter group died. There was no correlation between hemobilia and hemostatic or hepatic insufficiency. Angiography during PTBD was performed in 47 patients, and abnormalities restricted to arterial changes were noted in nine (19.1%). All but one patient with hemobilia showed angiographic abnormalities. Our findings indicate that hemobilia occurs more often than has been suspected and that it is usually due to intrahepatic vessel injury rather than to hemorrhagic diathesis or hepatic insufficiency. The primary management of hemobilia consists of maintaining continuous patency of the drainage catheter.